Field of the Invention
Embodiments of the present invention relate to a printed circuit board and a lighting unit including the printed circuit board that can be easily manufactured and designed.
Description of the Related Arts
According to the development of electronics industries, various display devices have been developed, and imaging devices, computers, mobile communication terminals and the like using the display devices have been also developed. A liquid crystal display appearing by reflecting this trend has been widely used as a display for a monitor, a mobile communication terminal and the like.
A liquid crystal display (LCD) results from applying electro-optical properties of liquid crystal having an in-between characteristic of a liquid and a solid to a display device, and is an electrical device that changes various kinds of electrical information generated from various devices to visual information and transmit the changed visual information using a variation in transmittance of liquid crystal resulting from an applied voltage. It is advantageous in that the LCD has low power consumption due to a low operating voltage and is also portable
Since the LCD has no self-luminous which can make its own light, a backlight is needed. A backlight serves a light source of LCDs and refers to a complex composed of a light source itself for irradiating light to a rear surface of a liquid module, a power circuit for driving the light source, and all components for enabling uniform flat light to be formed.
A backlight unit using a light emitting diode (LED) has been suggested as a light source for illumination of the LCD. An LED is a light emitting element generating light using a photoemission phenomenon generated when a voltage is applied to a semiconductor. The LED is small in its size and has a long lifespan compared to existing light sources. In addition, it is advantageous in that the LED has high energy efficiency and a low operating voltage because it directly converts electrical energy into light energy.
The liquid crystal display device becomes gradually thin, and accordingly, a reduction in a width of the liquid crystal display device has been needed.
FIGS. 1 to 3 are views illustrating a printed circuit board of a backlight unit according to a conventional art wherein FIG. 2 is a cross sectional view taken along lines A-A′ of the printed circuit board of FIG. 1, and FIG. 3 is a perspective view of the printed circuit board according to the conventional art.
As illustrated in FIG. 1, a printed circuit board (PCB) is configured such that a mounting pad 12 is formed, a light emitting element 15 is mounted to the mounting pad 12, and a string wiring 13 electrically connected to the mounting pad 12 and transmitting an electrical signal to the light emitting element 15 is formed.
Referring to FIG. 2, it can be seen that the printed circuit board according to the conventional art is configured such that both the mounting pad 12 to which the light emitting element 15 is mount, and the string wiring 13 are disposed on an insulating layer formed on a substrate 10.
However, according to the conventional art, as illustrated in FIG. 3, when the printed circuit board is subjected to bending treatment, since the mounting pad 12, the light emitting element 15, and the string wiring 13 are disposed in a mounting area 30, it is problematic in that it is difficult to realize slimming of a product to which the printed circuit board is applied due to a width of the mounting area 30.